It is proposed to deploy a small-cell wireless communication base station device that covers a small-zone area of several tens meters, such as homes, offices, and so on, in addition to a macro cell that is a currently-used large cell in an existing mobile communication system. Such a small-cell wireless communication base station device is called a “Home Node B (HNB)”.
Furthermore a Closed Subscriber Group (CSG) Cell is also studied as the function of the HNB which allows access to only limited group members, e.g., family members of the home where the HNB is deployed.
On the other hand, in the existing mobile communication system, various Radio Access Technologies (RATs), e.g., W-CDMA (Wideband Code Division Multiple Access), LTE (Long-term evolution), WLAN (Wireless LAN), WiMAX (Worldwide Interoperability for Microwave Access), exist together. Thus, the cover areas of plural RATs overlap each other in a service area of a mobile communication system.
In such a mobile communication system, a mobile station is required to be able to detect which cover area of RATs the mobile station locates and what communication services the mobile station can receive now. For instance, when the cover area of WLAN is included in a part of the cover area of LTE, a mobile station located in the cover area of WLAN cannot receive communication services of WLAN and can receive only communication services of LTE, unless the mobile station can detect that it is now positioned in the cover area of WLAN.
As related art, there is a technique enabling a mobile station to detect the cover area of RATs where the mobile station locates now, by a base station of a RAT (e.g., LTE) notifying information of another RAT (e.g., WLAN) to the mobile station based on the location information of the mobile station (see Non Patent Literature (NPL) 1).
Another related art proposes that a base station of LTE utilizes the physical property of a part of its transmit signal to notify the presence of another RAT (see Patent Literature (PTL) 1).